School absenteeism is a major societal problem, with a range of potential adverse long-term consequences. This scoping review aimed to provide a comprehensive overview of the research on school absenteeism in autistic children and adolescents, expose important gaps in the literature, and explore possibilities for future systematic reviews. Five relevant databases were searched systematically from inception to June 2023, yielding a total of 46 eligible reports from 42 separate studies. All studies were conducted in high-income countries, and most were published in the last decade. Three major themes emerged: occurrence, contextual factors, and interventions. The results of large-scale population-based studies clearly suggested that autistic children and adolescents were absent from school more often than their non-autistic peers, which partly was attributable to co-occurring conditions. Bullying also emerged as a potential risk factor. Only a few preliminary studies were available on targeted interventions, emphasizing the need for more robust studies. More research is also needed on the mechanisms leading to and maintaining school absenteeism in this group of learners. Overall, the diversity of research questions, methods, and definitions used in this body of research suggests that systematic reviews with narrow focus on a few key questions may still be premature. Lay abstract Autistic children and teenagers are, on average, absent from school more than their peers. The aim of this review was to provide an overview of the research on absence from school in autistic learners in primary and secondary school, to help guide future research. We sifted through 4632 reports and found 42 studies with a focus on school absence and autism. We looked at how, when, and where the studies were conducted. We also summarized the results and outlined how absence was measured in the studies. Absence from school may lead to problems later in life, like incomplete education and unemployment. It is therefore important to know how common this problem is among autistic learners, what the reasons may be, and what type of support they need. The studies were from high-income countries and were mainly published in the last 10 years. Studies based on school registers from the United States and the United Kingdom clearly showed that children and teenagers with autism had higher risk of school absence than those without autism. Absence was often linked to problems with mental health or additional neurodevelopmental conditions. Several studies also showed that absence in autistic children and adolescents was related to problems in school, like bullying or lack of knowledge about autism. Support programs were only evaluated in a few studies with a small number of study participants. We conclude that more research is needed to better understand why autistic learners are absent and what they need to thrive in school.